U.S. patent number 10,530,231 [Application Number 15/776,788] was granted by the patent office on 2020-01-07 for linear vibration motor.
The grantee listed for this patent is GOERTEK INC.. Invention is credited to Chunfa Liu, Fenglei Zu.
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United States Patent |
10,530,231 |
Liu , et al. |
January 7, 2020 |
Linear vibration motor
Abstract
A linear vibration motor includes a vibration block having
permanent magnets and magnetic conductive yokes between adjacent
permanent magnets; and a stator having stator coils arranged
corresponding to the vibration block and magnetic conductive cores
in the stator coils, a magnetic conductive brush being fixed on the
magnetic conductive cores and a brush head of the brush being in
elastic contact with the magnetic conductive yokes; or, a magnetic
conductive brush being fixed on the magnetic conductive yokes and
the brush head of the brush being in elastic contact with the
magnetic conductive cores. The magnetic field lines generated by
the vibration block can be concentrated to be conducted to the
stator coils, thereby maximizing the effective magnetic field of
the vibration block to improve the acting force between the
vibrator and the and obtain an intensified vibration effect.
Inventors: |
Liu; Chunfa (Shandong,
CN), Zu; Fenglei (Shandong, CN) |
Applicant: |
Name |
City |
State |
Country |
Type |
GOERTEK INC. |
WeiFang, Shandong |
N/A |
CN |
|
|
Family
ID: |
55332613 |
Appl.
No.: |
15/776,788 |
Filed: |
May 19, 2016 |
PCT
Filed: |
May 19, 2016 |
PCT No.: |
PCT/CN2016/082564 |
371(c)(1),(2),(4) Date: |
May 17, 2018 |
PCT
Pub. No.: |
WO2017/088366 |
PCT
Pub. Date: |
June 01, 2017 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20180375415 A1 |
Dec 27, 2018 |
|
Foreign Application Priority Data
|
|
|
|
|
Nov 25, 2015 [CN] |
|
|
2015 1 0835630 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H02K
33/18 (20130101); H02K 33/00 (20130101) |
Current International
Class: |
H02K
33/18 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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101221865 |
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Jul 2008 |
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CN |
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102035343 |
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Apr 2011 |
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CN |
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102570764 |
|
Jul 2012 |
|
CN |
|
103378703 |
|
Jan 2013 |
|
CN |
|
103620929 |
|
Mar 2014 |
|
CN |
|
104660106 |
|
May 2015 |
|
CN |
|
105356712 |
|
Feb 2016 |
|
CN |
|
205283369 |
|
Jun 2016 |
|
CN |
|
H11155274 |
|
Jun 1999 |
|
JP |
|
2010179295 |
|
Aug 2010 |
|
JP |
|
Primary Examiner: Desai; Naishadh N
Attorney, Agent or Firm: Themis Law
Claims
The invention claimed is:
1. A linear vibration motor, comprising: a vibration block; and a
stator arranged in parallel with the vibration block, wherein: the
vibration block comprises at least two adjacent permanent magnets
and a magnetic conductive yoke arranged between each two of the at
least two adjacent permanent magnets; the stator comprises a stator
coil arranged corresponding to the vibration block and a magnetic
conductive core arranged in the stator coil, and wherein: a
magnetic conductive brush is fixed on the magnetic conductive core
of the stator, and a brush head of the magnetic conductive brush is
in elastic contact with the magnetic conductive yoke of the
vibration block; or a magnetic conductive brush is fixed on the
magnetic conductive yoke of the vibration block, and a brush head
of the magnetic conductive brush is in elastic contact with the
magnetic conductive core of the stator.
2. The linear vibration motor according to claim 1, wherein: the
vibration block comprises three permanent magnets arranged side by
side and two magnetic conductive yokes arranged between each two
adjacent permanent magnets, and polarities of adjacent ends of each
two adjacent permanent magnets are the same; and the stator
comprises one or more stator coils arranged at one side or both
upper and lower sides of the vibration block and one or more
magnetic conductive cores correspondingly arranged in the one or
more stator coils, and an axis direction of the one or more stator
coils is perpendicular to a magnetization direction of the
permanent magnets of the vibration block.
3. The linear vibration motor according to claim 2, wherein the
magnetic conductive brush has a herringbone structure or an
arc-shaped structure; and wherein a middle top end of the magnetic
conductive brush is fixed on the one or more magnetic conductive
cores of the stator, and brush heads provided at two side ends of
the magnetic conductive brush are respectively in elastic contact
with the two magnetic conductive yokes of the vibration block; or
two side ends of the magnetic conductive brushes are respectively
fixed on the two magnetic conductive yokes of the vibration block,
and a brush head provided at a middle top end of the magnetic
conductive brush is in elastic contact with the one or more
magnetic conductive cores of the stator.
4. The linear vibration motor according to claim 1, wherein the
magnetic conductive brush is a bent copper sheet.
5. The linear vibration motor according to claim 1, wherein: the
stator comprises one or more stator coils arranged at one side or
both upper and lower sides of the vibration block and one or more
magnetic conductive cores correspondingly arranged in the one or
more stator coils; and an axis direction of the stator one or more
coils is perpendicular to a magnetization direction of the
permanent magnets of the vibration block.
6. The linear vibration motor according to claim 5, wherein: the
stator coils correspondingly arranged at both upper and lower sides
of the vibration block are parallel to each other, and axes of the
stator coils are located on a same straight line; and current
directions in the stator coils correspondingly arranged at upper
and lower sides of the vibration block are opposite.
7. The linear vibration motor according to claim 1, wherein a
horizontal distance d between the magnetic conductive yoke and the
magnetic conductive core is in a numerical range of 0.1 mm to
0.3mm.
8. The linear vibration motor according to claim 1, further
comprising: a counterweight block having a one-piece structure,
wherein a receiving groove for accommodating the vibration block is
provided at a middle position of the counterweight block; and an
avoidance structure for avoiding the stator is provided in the
counterweight block at a position corresponding to the stator.
9. The linear vibration motor according to claim 8, further
comprising a housing, wherein: the counterweight block has a
one-piece structure, grooves are symmetrically arranged at two ends
of the counterweight block, and push-pull magnets are accommodated
and fixed in the grooves; and push-pull coils surrounding the
push-pull magnets are fixedly arranged on the housing at positions
corresponding to the push-pull magnets, respectively.
10. The linear vibration motor according to claim 9, further
comprising push-pull coil bobbins on which the push-pull coils are
wound respectively.
Description
TECHNICAL FIELD OF THE INVENTION
The present invention relates to technical field of consumer
electronic, and more particularly, relates to a linear vibration
motor for portable consumer electronic products.
BACKGROUND OF THE INVENTION
With the development of communication technology, portable
electronic products such as mobile phones, handheld game player or
handheld multimedia entertainment apparatus have come up to
people's lives. In these portable electronic products, micro
vibration motors are generally used for providing system feedback,
such as mobile phones notification on an incoming call, game
player's vibration feedback and the like. However, with the
development tendency for electronic products to be lightening and
thinning, a variety of internal components thereof also need to
suitable for this tendency, and micro vibration motor is no
exception.
The existing micro vibration motor generally comprises an upper
cover, a lower cover which forms a vibration space with the upper
cover, a vibrator (including a counterweight block and a permanent
magnetic) performing a linear reciprocate vibration in the
vibration space, an elastic support member connecting to the upper
cover and driving the vibrator to perform a reciprocate vibration,
and a stator coil located under the vibrator by a certain
distance.
In the micro vibration motor with the above described structure,
the magnetic members in the vibrator are disposed side by side and
have the same magnetization direction, after the coil is energized,
the stator will be subject to the Lorentz force which drives the
stator to move, and the vibrator will be subjected to an acting
force in the opposite direction by the relationship between the
acting force and the reacting force and perform a linear vibration
drove by this force. However, in the micro vibration motor of the
above described structure, the magnetic field lines generated by
the magnetic members in the vibrator are relatively dispersed, and
the magnetic conductive strength between the vibrator and the
stator is relatively weak, and correspondingly, the magnetic flux
passing through the coil is also relatively small, thus the force
generated thereby is relatively small, which disadvantageously
affects the vibration effect.
SUMMARY OF THE INVENTION
In view of the above problems, the purpose of the present invention
is to provide a linear vibration motor, which utilizes a magnetic
conductive structure additionally provided between a stator and a
vibrator to concentrate and guide the magnetic field generated by
the vibration block to the stator coil, so as to maximize the
effective magnetic field of the vibration block, thereby improving
the acting force between the vibrator and the stator and obtaining
an intensive vibration effect.
The present invention provides a linear vibration motor comprising
a vibration block and a stator arranged in parallel with the
vibration block, and the vibration block comprises at least two
adjacent permanent magnets and magnetic conductive yokes arranged
between each two of the at least two adjacent permanent magnets,
the stator comprises a stator coil arranged corresponding to the
vibration block and a magnetic conductive core arranged in the
stator coil, wherein a magnetic conductive brush is fixed on the
magnetic conductive core of the stator, and a brush head of the
magnetic conductive brush is in elastic contact with the magnetic
conductive yoke of the vibration block, or a magnetic conductive
brush is fixed on the magnetic conductive yoke of the vibration
block, and a brush head of the magnetic conductive brush is in
elastic contact with the magnetic conductive core of the
stator.
According to a preferred embodiment, the vibration block comprises
three adjacent permanent magnets arranged side by side and two
magnetic conductive yokes arranged between each two adjacent
permanent magnets, and polarities of adjacent ends of each two
adjacent permanent magnets are the same, and the stator comprises
stator coil(s) arranged at one side or both upper and lower sides
of the vibrator and magnetic conductive core(s) correspondingly
arranged in the stator coil(s), and an axis direction of the stator
coil(s) is perpendicular to a magnetization direction of the
permanent magnets of the vibration block.
According to a preferred embodiment, the magnetic conductive brush
has a herringbone structure or an arc shaped structure, wherein a
middle top end of the magnetic conductive brush is fixed on the
magnetic conductive core(s) of the stator, and brush heads provided
at the two side ends of the magnetic conductive brush are
respectively in elastic contact with the two magnetic conductive
yokes of the vibration block, or two side ends of the magnetic
conductive brushes are respectively fixed on the two magnetic
conductive yokes of the vibration block, and a brush head provided
at a middle top end of the magnetic conductive brush is in elastic
contact with the magnetic conductive core(s) of the stator.
According to a preferred embodiment, the magnetic conductive brush
is a bent copper sheet.
According to a preferred embodiment, the stator comprises stator
coil(s) arranged at one side or both upper and lower sides of the
vibration block and magnetic conductive core(s) correspondingly
arranged in the stator coil(s), and an axis direction of the stator
coils is perpendicular to a magnetization direction of the
permanent magnets of the vibration block.
According to a preferred embodiment, the stator coils
correspondingly arranged at upper and lower sides of the vibration
block are parallel to each other and the axes thereof are located
on a same straight line; current directions in the stator coils
correspondingly arranged at upper and lower sides of the vibration
block are opposite.
According to a preferred embodiment, a horizontal distance d
between the magnetic conductive yoke and the magnetic conductive
core in the horizontal direction is in a numerical range of 0.1 mm
to 0.3 mm.
According to a preferred embodiment, the linear vibration motor
further comprises a counterweight block having a one-piece
structure, and a receiving groove for accommodating the vibration
block is provided at a middle position of the counterweight block,
and an avoidance structure for avoiding the stator is provided in
the counterweight block at a position corresponding to the
stator.
According to a preferred embodiment, the linear vibration motor
further comprises a housing, and the counterweight block has a
one-piece structure, and grooves are symmetrically arranged at two
ends of the counterweight block, and push-pull magnets are
accommodated and fixed in the grooves; push-pull coils surrounding
the push-pull magnets are fixedly arranged on the housing at
positions corresponding to the push-pull magnets, respectively.
According to a preferred embodiment, the linear vibration motor
further comprises push-pull coil bobbins on which the push-pull
coils are wound, respectively.
The above described linear vibration motor according to the present
invention utilizes a magnetic conductive brush arranged between the
stator and the vibration block to enable the magnetic field lines
generated by the vibration block to be concentrated and conducted
to the stator coils, thereby maximizing the effective magnetic
field of the vibration block to improve the acting force between
the vibrator and the stator and obtain a more intense vibration
effect.
In order to achieve the above and related object, one or more
aspects of the present invention comprise the features that will be
described below in detail and particularly set forth in claims. The
following description and the drawings explain certain illustrative
aspects of the present invention in detail. However, these aspects
are merely some of the various embodiments which can utilize the
principles of the present invention. In addition, the present
invention is intended to comprise all these aspects and their
equivalents.
BRIEF DESCRIPTION OF THE DRAWINGS
The other purposes and results of the present invention will become
more clear and easy to understand through the following
descriptions in combination with the accompanying drawings and
contents of claims, along with more fully understood of the present
invention. In the drawings:
FIG. 1 is a schematic diagram of an overall exploded structure of a
linear vibration motor according to the first embodiment of the
present invention;
FIG. 2 is a sectional diagram of a combination structure of a
linear vibration motor according to the first embodiment of the
present invention;
FIG. 3a and FIG. 3b are schematic diagrams of a magnetic conductive
driving principle according to the first embodiment of the present
invention;
FIG. 4a and FIG. 4b are schematic structural diagrams of a magnetic
conductive brush according to the first embodiment and the second
embodiment of the present invention, respectively;
FIG. 5 is a schematic structural diagram of a counterweight block
according to an embodiment of the present invention; and
FIG. 6a and FIG. 6b are schematic diagrams of a combination
structure of a vibration block and a stator according to an
embodiment of the present invention respectively.
The reference numerals include: an upper housing 1, a lower cover
11, a push-pull coil 2, a coil bobbin 3, a push-pull magnet 4, a
magnetic conductive block 42, a counterweight block 5, grooves 51,
a receiving groove 52, a magnetic conductive brush 58, permanent
magnets 81, 82, 83, magnetic conductive yokes 91, 92, stator coils
61, 62, magnetic conductive cores 71, 72, and spring plate 10
The same reference numbers indicate similar or corresponding
features or functions in all of the drawings.
DETAILED DESCRIPTION OF EMBODIMENTS
In the following description, for the purposes of explanation,
various specific details are described in order to provide a full
understanding of one or more embodiments. However, it is apparent
that these embodiments can be implemented without these specific
details. In other examples, well-known structures and apparatus are
illustrated in form of block diagram in order to facilitate
describing the one or more embodiments.
The "counterweight block" used in the following detailed
description of embodiments may also be referred to as "mass block",
and both of them refer to a block having heavy mass and is made of
high density metal which is fixed to a vibration block that
generating vibration for vibration balance.
In addition, the present invention is mainly focus on the
improvement in micro vibration motors, but it is not excluded that
the technology disclosed in the present invention can be applied to
a large vibration motor. However, in order to facilitate
describing, in the following description of the embodiments,
"linear vibration motor" and "micro vibration motor" refer to the
same thing.
In the following, the particular embodiments of the linear
vibration motor according to the present invention will be
described in detail with reference to the accompanying
drawings.
In order to solve the problem that the magnetic field lines are
dispersed in the structure of the existing micro vibration motor,
the present invention provides a linear vibration motor in which a
magnetic conductive brush is arranged between the stator and the
vibration block, and the magnetic field strength between the
vibrator and the stator is improved by the magnetic conductive
brush, so as to maximize the effective magnetic field strength of
the vibration block within a limited space, thereby improving the
acting force between the vibrator and the stator and effectively
improving the vibration force of the micro vibration motor without
increasing the volume of the micro vibration motor.
The linear vibration motor according to the present invention
comprises a vibration block and a stator arranged in parallel with
the vibration block, and the vibration block comprises at least two
adjacent permanent magnets and a magnetic conductive yoke arranged
between the adjacent permanent magnets; the stator comprises a
stator coil arranged corresponding to the vibration block and a
magnetic conductive core arranged in the stator coil, and a
magnetic conductive brush is arranged between the stator and the
vibration block, and the upper end and lower end of the magnetic
conductive brush are in elastic contact with the magnetic
conductive yoke of the vibration block and the magnetic conductive
core of the stator respectively. Specifically, when the magnetic
conductive brush is fixed onto the magnetic conductive core of the
stator, the brush head of the magnetic conductive brush is in
elastic contact with the magnetic conductive yoke of the vibration
block; alternately, when the magnetic conductive brush is fixed
onto the magnetic conductive yoke of the vibration block, the brush
head of the magnetic conductive brush is in elastic contact with
the magnetic conductive core of the stator.
That is to say, in the present invention, aiming at improving the
magnetic field strength between the stator and the vibrator, a
magnetic conductive brush is additionally provided between the
vibration block and the stator, such that the magnetic field
lines/magnetic induction lines generated by the vibration block can
be more concentrated to pass through the stator coils, so as to
increase the utilization rate of the magnetic field of the
vibrating block.
The technical solution of the present invention will be described
in more detail by the following two specific embodiments.
In particular, FIGS. 1, 2, 3a and 3b are respectively a schematic
diagram of an overall exploded structure, a sectional diagram of an
assembled structure, and a diagram illustrating driving principle
of a linear vibration motor according to the first embodiment of
the present invention.
As shown in FIGS. 1 and 2, the linear vibration motor according to
the first embodiment mainly comprises a housing, a vibrator, and a
stator, and the stator is fixed on the housing and is arranged in
parallel with the vibrator, wherein the housing comprises an upper
housing 1 and a lower cover 11; the vibrator comprises a
counterweight block 5 and a vibration block embedded and fixed in
the counterweight 5; the vibration block comprises three adjacent
permanent magnets 81, 82, and 83; and magnetic conductive yokes 91,
92 disposed between adjacent permanent magnets. The stator
comprises stator coils 61 and 62 correspondingly arranged at the
upper and lower sides of the vibration block, and magnetic
conductive cores 71 and 72 respectively arranged in the stator
coils 61 and 62. The magnetization direction of the permanent
magnets in the vibration block and the axis direction of the stator
coils are perpendicular to each other, and the magnetic conductive
yokes in the vibration block and the magnetic conductive cores in
the corresponding stator are arranged in a misaligned manner.
The magnetic conductive brush 58 has an arc-shaped structure and is
arranged between the vibration block and the stator, wherein the
brush heads of the magnetic conductive brush may be provided at the
two side ends or at the top end of the magnetic conductive brush.
The protruded top end of the arc-shaped magnetic conductive brush
58 is in contact with the magnetic conductive cores 71, 72 of the
stator, and the two side ends of the magnetic conductive brush 58
are in contact with the two magnetic conductive yokes 91, 92 of the
vibration block, respectively. Specifically, when the top end of
the magnetic conductive brush 58 at the middle position thereof is
fixed on the magnetic conductive cores 71, 72 of the stator, the
brush heads arranged at the two side ends of the magnetic
conductive brush 58 are in contact with the two magnetic conductive
yokes 91, 92 of the vibration block respectively; alternatively,
when the two side ends of the magnetic conductive brush 58 are
fixed onto the two conductive yokes 91, 92 of the vibration block
respectively, the brush head provided at the middle top end of the
magnetic conductive brush 58 is in contact with the magnetic
conductive cores 71, 72 of the stator. According to the schematic
diagram of the vibration principle shown in FIGS. 3a and 3b, it can
be seen that the magnetic field lines generated by the vibration
block respectively pass through the stator coils vertically upward
and downward. According to the left hand rule determining the
direction of force that an energized conductor is subject to in a
magnetic field and the current directions in the stator coils, the
stator coils are subjected to leftward forces, wherein the current
direction indicated by ".circle-w/dot." is perpendicularly to the
drawing plane and directed outwards, and the current direction
indicated by "" is perpendicularly to the drawing plane and
directed inward. Since the stator coils are fixed and immovable,
the vibration block is subjected to a rightward force F based on
the relationship between the acting force and the reacting force.
In this way, when the vibration block is subjected to a rightward
driving force, the vibration block will drive and perform a
rightward translational movement together with the counterweight
block. Similarly, when the directions of the currents change, the
stator coils are subjected to rightwards magnetic forces according
to the left hand rule. Since the stator coils are fixed and
immovable, the vibration block is subjected to a leftward force
with opposite direction and the same magnitude, and the vibration
block which is subjected to a leftward driving force will drive and
perform a leftward translational movement together with the
counterweight block. The above described movements are alternately
performed, thereby driving the micro vibration motor to
vibrate.
By providing the magnetic conductive brush 58, the originally
dispersed magnetic field lines conducted by the magnetic conductive
yokes in the vibration block are conducted and concentrated by the
magnetic conductive brush to pass through the magnetic conductive
cores of the stators provided at the upper and lower sides, thereby
maximizing the magnetic flux passing through the stator coils and
making the magnetic field of the vibration block can be effectively
utilized.
In the specific application process, as the magnetic conductive
brush, it can be considered to utilize a copper sheet bent into a
specific structure or a magnetic conductive material having elastic
structure such as an elastic plastic sheet coated with a magnetic
conductive material.
FIGS. 4a and 4b are schematic structural diagrams of magnetic
conductive brushes according to the first embodiment and the second
embodiment of the present invention, respectively.
As shown in FIG. 4a, the magnetic conductive brush according to the
first embodiment has an arc-shaped structure, and the magnetic
conductive brush according to the second embodiment shown in FIG.
4b has a herringbone structure, wherein the top end of the
herringbone at middle portion of the magnetic conductive brush is
in contact with the magnetic conductive core of the stator, and two
side ends thereof are in contact with the two magnetic conductive
yokes of the vibration block respectively. Specifically, when the
middle top end of the magnetic conductive brush is fixed on the
magnetic conductive core of the stator, the brush heads provided at
two side ends of the magnetic conductive brush are in contact with
the two magnetic conductive yokes of the vibration block
respectively. Alternatively, when the two side ends of the magnetic
conductive brush are fixed on the two magnetic conductive yokes of
the vibration block respectively, the brush head provided at the
middle top end of the magnetic conductive yoke is in contact with
the magnetic conductive core of the stator.
The linear vibration motor according to the first embodiment has a
sandwich structure, i.e., an arrangement of the stators and the
vibrator in the vertical direction is "stator-vibrator-stator". It
also can be seen from the drawings that the stators comprises
stator coils correspondingly arranged at the upper and lower sides
of the vibration block and magnetic conductive cores arranged in
the stator coils, and the stator coils correspondingly arranged at
the upper and lower sides of the vibration block are parallel to
each other and have opposite current directions. However, the
linear vibration motor of the present invention is not limited to
the sandwich structure shown in the first embodiment, but may also
be designed as a structure with stator(s) arranged at one side
thereof, i.e., the stator comprises stator coil(s) arranged at one
side of the vibration block and magnetic conductive core(s)
arranged in the stator coil(s), and the magnetization direction of
the permanent magnet in the vibration block is perpendicular to the
axis direction of the stator coil(s). The number and types
(electromagnets, permanent magnets, magnetic conductive cores,
etc.) constituting the stator and the combination manners thereof,
as well as the number (e.g., two magnets) and types
(electromagnets, permanent magnets, magnetic conductive cores,
etc.) of magnets constituting the vibration block and the
combination manners thereof can be appropriately selected according
to the magnitude of the vibration force required by the products to
which it is applied. More combination structures of the vibration
block and the stator are shown in FIGS. 6a and 6b.
In addition, in a preferred embodiment of the present invention, it
is also possible to additionally provide the linear vibration motor
with additional push-pull mechanisms at two ends of the vibration
block, and by utilizing the interaction force between the push-pull
magnets fixed in the counterweight block and the push-pull coils
fixed on the housing, it can provide a driving force for the
reciprocating motion of the vibrator in a direction parallel to the
plane where the stator is located.
Specifically, as shown in the embodiment of FIG. 1, the push-pull
magnets 4 are symmetrically arranged at two ends of the vibrator,
and push-pull coils 2 surrounding the push-pull magnets 4 are
fixedly arranged on the housing at positions corresponding to the
push-pull magnets 4, and the push-pull coils 2 are wound around the
push-pull coil bobbins 3. After the push-pull coils 2 are
energized, push-pull forces in the horizontal direction are
generated between the push-pull coils 2 interaction and the
push-pull magnets 4, so as to provide a driving force for the
reciprocating motion of the vibrator in a direction parallel to the
plane where the stator is located.
According to the vibration principle of the conventional motor,
after the coil in the stator is energized, interactional push-pull
forces are generated between the permanent magnets in the vibration
block and the coils in the stators, which interact with each other,
and the directions of the magnetic field lines generated by the
stators are changed by changing the current directions of the coils
in the stators, so as to drive the vibrator to reciprocally move in
a direction parallel to the plane where the stator is located.
However, in the micro vibration motor, due to the limitation on the
volume of the micro vibration motor, the driving force that the
original driving members can provide is extremely limited. In the
present invention, however, the additionally provided drive
structure composed of the push-pull magnets at two ends of the
vibrator and the push-pull coils fixed on the housing can provide
an additional driving force for the micro vibration motor, thereby
effectively improving the vibration force of the micro vibration
motor without increasing the volume of the micro vibration
motor.
FIG. 5 shows the structure of a counterweight block according to an
embodiment of the present invention.
As shown in FIG. 5, the counterweight block 5 has a one-piece
structure. A receiving groove 52 for accommodating a vibration
block is provided in the middle of the counterweight block 5, and
grooves 51 for accommodating push-pull magnets are provided at two
ends of the counterweight block. In addition, an avoidance
structure for avoiding the stator is further provided at a position
corresponding to the middle of the counterweight block, and a
receiving groove 52 for accommodating the vibration block is
provided at the center of the avoidance structure. In the specific
process for assembling the counterweight block, the permanent
magnets and the magnetic conductive yokes constituting the
vibration block can be fixed together, and then the vibration block
can be integrally fixed in the receiving groove 52 by means of
coating with adhesive or laser welding, and the push-pull magnets 4
may also be fixed in the grooves 51 in a similar manner. In
addition, in the first embodiment, the push-pull magnet 4 is a
one-piece permanent magnet which is magnetized in the horizontal
direction, and the axial directions of the push-pull coils 2 are
parallel to the magnetization directions of the push-pull magnets
4.
The counterweight block 5 may be a block made of high density metal
materials, such as a tungsten steel block, a nickel steel block or
a nickel-tungsten alloy block, so as to increase the vibration
force and make the vibration of the electronic product more
intense.
As can be seen from FIGS. 2 and 5, since the grooves 51 for
accommodating the push-pull magnets are arranged at two ends of the
counterweight block 5, the additionally provided push-pull magnets
do not increase the length or thickness of the vibrator, and the
push-pull coils arranged surrounding the push-pull magnets are
fixed on the housing, utilizing the avoidance space in the
conventional motor structure, which also do not increase the volume
of the micro vibration motor.
In the embodiments of the present invention, vibration reduction
and collision prevention of the vibrator during vibration are
achieved through elastic pieces respectively arranged at two ends
of the vibrator. As shown in FIGS. 1 to 3, the elastic pieces 10
are located and fixed between the vibrator and the housing. The
vibrator squeezes the elastic piece at one end during vibration,
and the squeezed elastic piece can prevent the vibrator from
colliding with the housing during the vibration. Meanwhile, the
squeezed elastic piece can also provide an elastic restoring force
in the opposite direction for the vibration of the vibrator.
In the above described embodiments, the magnetic conductive yokes
in the vibration block and the corresponding magnetic conductive
cores in the stators are arranged in a misaligned manner, and a
horizontal distance d between the magnetic conductive yokes in the
vibration block and the magnetic conductive cores in the stators
corresponding to the magnetic conductive yokes is in the numerical
range of 0.1 mm, 0.3 mm. That is, the horizontal distance between
the center line of each magnetic conductive yoke and the center
line of the magnetic conductive core of the corresponding (i.e.,
nearest) stator is 0.1 to 0.3 mm. Therefore, the left-right offset
distance between the center axis of the vibration block and the
center axis of the vibration block in stationary state is 0.2 mm
when the vibration block drives the counterweight block to move
reciprocally. Accordingly, the distance between the edge of the
avoidance structure and the outer edge of the stator should be
slightly larger than 0.2 mm.
In addition, the linear vibration motor according to the present
invention further comprises a flexible printed circuit board
(PFCB), and the stator may be fixed on the FPCB. The stator coil
lead wires are connected to the external circuit through the
circuit on the FPCB, and the FPCB is fixed to the housing.
The linear vibration motor according to the present invention is
described by way of example with reference to the accompanying
drawings. However, those skilled in the art should understand that
various modifications can be made to the linear vibration motor
according to the present invention without departing from the
contents of the present invention. Therefore, the protection scope
of the present invention should be determined by the contents of
the appended claims.
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